The Rice-VariarmFebruary 1941
QST Article

Wax nostalgic about and learn from the history of early electronics. See articles
from ARRL's QST, published December 1915 - present. All copyrights hereby acknowledged.

Electron-coupled
oscillators (ECOs)
were a real breakthrough in achieving frequency stability in harsh
environments that included mechanical vibration, temperature excursions,
power supply variations, and load changes. Use of vacuum tubes made
the task even more challenging. Such oscillators were necessarily
very expensive compared to less sophisticated designs. Henry E.
Rice Jr., W9YZH, introduced his "Rice Variarm" model (aka the Millen
Model 90700) at a breakthrough price of just $29.50, which in 2013
money equates to $469.89 per the U.S. BLS
Inflation Calculator. That is a lot of moola for amateur radio
operators even today. The arm sticking out of the case is for adjusting
the frequency.

The Rice-Variarm

Something Radically New in ECOs

There are many approaches to the ECO design, most of them
having been described in the past; such as expensive, ruggedly-built
h.f. oscillators with their external regulated power supplies, low-frequency
dual heterodyne oscillators, etc. All have their merits, but are
necessarily expensive to manufacture and must ultimately end up
by selling in the 50 to 60 dollar price bracket.

A new approach
to this problem has been evolved by Henry Rice, Jr., and was described
in detail in January OST. Probably the outstanding feature of the
Rice development is its high-performance-per-dollar which makes
possible a factory built commercial ECO with modern performance,
complete with tubes, ready to use, for less than 30 dollars!

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling
2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas
and reference material while performing my work as an RF system and circuit design engineer.
The Internet was still largely an unknown entity at the time and not much was available
in the form of WYSIWYG
...

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